Impact strength of aged b-titanium alloy (Ti-15V-3C- 3Sn-3Al)
Ogawa Kinya
Abstract:Compressive strength of b-Titanium alloy (Ti-15V-3Cr-3Sn-3Al) aged at 723 K for 6 hours, as ( a + b ) two phase alloy, was clarified in a wide range of temperature from 77 K to 673 K and at strain rates from 10-4 to 103s-1. Thermally activated strain rate analysis (TASRA) was applied to characterize the deformation mechanism. Adiabatic heating and strain rate change effect were taken into account to predict the stress strain relation at high strain rate, and the experimental results were well convincing. The strain rate sensitivity of stress under constant mobile dislocation density predicts the temperature and strain rate dependences of flow stress in the high strain rate range, while the deformation behaviour in the relatively low strain rate range is understood with due regard to the change of mobile dislocation density. It is found that a single thermally activated process corresponding to a or b phase predominates the deformation behaviour at low and high temperatures, respectively, and may characterize the two phase alloy as a whole. Key Words:impact strength, aged b )-titanium alloy, thermal activity, adiabatic heating, strain rate change, two-phase alloy, strain rate sensitivity of stress